Self-locking push-button tuning mechanism



M. J. PIPER 2,482,026

SELF-LOCKING PUSH BUTTO TUNING MECHANISM Sept. 13, 1949.

Filed NOV. 14, 1947 2 Sheets-Sheet l INVENTOR ATTORNEY Sept. 113, 1949. M. J. PIPER SELF-LOCKING PUSH BUTTON TUNING MECHANISM 2 Sheets-Sheet 2 Filed Nov. 14, 1947 n m dm YQ. B

Patented Sept. 13, 1949 SELF-LOCKING PUSH-BUTTON TUNING MECHANISM Marion J. Pifer, Williamsville, N. Y., assignor to Colonial Radio Corporation, Buffalo, N. Y.

Application November 14, 1947, Serial No. 785,925

6 Claims.

This invention relates to a push button tuning mechanism for radio receivers, and more particularly to a self locking cam mechanism for rocher and tilt bar apparatus.

In the commonly used rocker and tilt bar mechanism, the rocker or cam is adjustably mounted on a plunger, and locked in the desired position by a plate which clamps the cam so that the cam is held by friction. The clamping plate is ordinarily wedged in position by means of a threaded rod, which is sometimes rotated by rotation of the push button, in case the push button is round, but by a'screw driver, in case the push button is square. In the latter instance, to make an adjustment of the cam such as is required in setting the push button to a new position, it is necessary for the user to remove the button and procure a screw driver or other tool, loosen the locking screw, reset the cam, tighten the locking screw, and replace the button.

It is an object of this invention to provide a mechanism in which no tools are required to reset the buttons, no clamping mechanism is employed, adjustments are greatly simplified, particularly where square push buttons are employed, and yet no parts of high precision, and consequently high cost, are employed.

It is a further object of this invention to provide such mechanism which ls capable of highand punch press parts, and which may be easily and quickly assembled with a minimum of expense.

Still other objects and advantages of my in' vention will be apparent from 'the specification.

The features of novelty which I believe to be characteristic of my invention are set forth vin the appended claims. My invention itself, however, both as to its fundamental principles and as to its particular embodiments, will best be understood by reference to the specification and accompanying drawing, in which Figure 1 is a top plan View of the tuner in accordance with my invention, partly broken away,

Figure 2 is a sectional View thereof on line 2-2 of Figure l,

Figure 3 is a view similar to Figure 2, but showing the mechanism in position for resetting a push button,

Figure 4 is a section on line 4--4 of Figure 2, and

Figure 5 is a detailed section of a modified form of cam.

The tuner mechanism is mounted in a frame which may be a stamping having a front plate I0, a bottom portion II, and end portion I2 and I3. Suitably secured to the front plate III at its upper portion, I am providing a bracket I4, provided with openings I5, I6, and II, to accommo-` date the push buttons employed, and registering openings may be provided in the front plate IIJ. In the present embodiment, I have illustrated only three push buttons for the sake of simplicity, but it will be understood that as many may be provided as desired. The buttons in this instance are indcated as I8, I9. and 20, and operate sliders or plungers 2I, 22, and 23.

In the present example of my invention, I have shown the tuner as operating permeability tuning cores 24, 25, and 26, attached to a carrier 21, and adapted to be moved longitudinally by tilt bar assembly 28. It will be understood, howl ever, that my invention may equally well be applied to operate other types of tuning mechanism such as variable condensers.

The tilt bar assembly may comprise upper and* lower bars 29 and 30, mounted in end plates 3l.` and 32, which in turn are mounted. in bearings 33 and 34 in the end plates I2 and I3. As will bei understood, the tilt bar assembly oscillates in the bearings 33 and 34, and the extended end plates 3| and 32 engage the core carrier 21 so as to move the cores 24, 25, and 26 longitudinally as the tilt bar oscillates.

In the embodiment of the invention now described, the stopping position of the tilt bar assembly 28 is determined by cams 35, 3B, and 31 for the respective push buttons I8, I9, and 20.

Each of these cams in the embodiment now described may comprise a wedge shaped stampingv of strip metal having registering screw threaded openings at the base of the wedge. Each cam` is mounted on a threaded rod, the rods being 40, 4I and 42 respectively, and each 'rod has nearits upper extremity a smaller unthreaded portion 43 (Figure 2), and each is provided at its lower extremity with a ball 44 resting in a socket 45 land with a projecting smaller end portion 4S extending through a clearance opening in theA socket 45. This permits the rods 4I), 4I, and 42 to tilt from the full line or operating position in Figure 2, to the dotted line or unused position.

It will be seen that by rotation of the rods 4I),

4I, and 42, their respective cams 35, 36, and 31 may be raised or lowered, and the position of these cams'determines the stopping position of tilt bar assembly 28. Each of the push button plungers 3l, 32, and 33 has a forked end portion 50, 5I, and 52, respectively, which engages the unthreaded portion of the threaded rods 4U, 4I,'

and 42 to tilt them from the position shown in 3 the dotted lines in Figure 2, to the full line position.

How the various cams may be adjusted by rotation of the rods on which they are mounted will now'be described.

A manual adjusting shaft 55 carrying knob 55 is mounted in brackets 51 on a bail 58 pivotally mounted on bearings 59 and 60 for slight rocking movement. The shaft 55 carries Vnear its `eX- tremity a Worm 6| engaging gear 62 secured to shaft 63, mounted in bearings 64 and 55 in the ball 58 and passing through clearance openings in end plates Il and i2.

The shaft 63 is threaded kfor engagement with gears 61, 68, and 69 secured on threaded rods 40, 4|, and 42, respectively. Bail 58 maybe spring biased to the position shown in Figure 3 by spring secured to extensions 1| and .12 of the bail and to the frame end plates H and i2. The dimensions are so related that Vwhen a push button vis depressed, .as in Figure 2, engagement between threaded sha-ft @6 and gears 6l, .68, and 69 still is not made. Engagement Vis made between any depressed push button, gear 61, :68, or 69 and the shaft 66 only when the manual adjusting knob 56, .is pushed downwardly, swinging lthe ball `counterclockWi-se from the position shown in Figure 2 to the position shown in Figure When 4this occurs, gear 61 68, or 69, as the case maybe, is engaged by shaft 53 and rotation of knob 56 will cause rotation of 'shaft 63, in turn rotating the respective rod 40, 4 I, or .42, and moving the respective cam 35, .36, or 31 upward or downward. This in turn `will cause partial rota.. tion of the tilt bar assembly 28 vto change the tuning :of the receiver.

Therefore, to set up a station, all that is necessary is to push in the desired button, push down knob 56, and rotate it until the desired station, for which the button is to be set, is timed in. When the knob 56 is released, its spring bias returns Vit to the position shown in .Figure 2, diseneasing shaft 53 from the respective gear 6?, 58, or 69. Repeated operation of any or `all of the push buttons, therefore, can not cause accidental movement of the cams from the preset position, because shaft 63 never engages the adjusting gears 61, 68, and 69 unless the knob is pushed down to the position shown in Figure 3.

fCams 35, 35, and 31 may take various forms. i

For instance, instead of the `wedge shape shown in .Figure 3, the cam may be in the for-m of an inverted wedge. or M, as at in Figure 5, and .in any ease, it may be desirable to extend one end of the cam to project through a clearance opening in the front plate I El. Springs 89 may be provided in each push :button to bias the same to outward position, the spring being attached on one end to the respective cam and to a suitable opening in the frame.

While I have shown and described certain preferred embodiments of `my invention, it will be understood that modifications and changes may be made without departing from the spirit and scope thereof, as will be clear to those skilled in the art.

In the specification I have .explained the principles of my invention and the best mode in which I have contemplated applying those principles, so .as to distinguish my invention from other inventions, and I have particularly pointed out and distinctly claimed the part, improvement, or combination which I claim as my invention or discovery.

I claim:

1. In a push button tuner, in combination, a frame, a plurality of plungers mounted in said frame, a plurality of tiltable levers pivotally mounted in said `frame for rocking motion when vactuated by said plungers respectively, cams adjustably positioned on said levers and movable longitudinally thereof, means for moving said cams longitudinally of said levers, and a tilt bar mounted in said frame for rocking motion, and for engagement with said cams.

I2. In .a push button tuner, in combination, a frame, a plurality of plungers mounted in said frame., a plurality of tiltable levers pivotally mounted in said frame for rocking motion when actuated 'by said plungers respectively, cams adjustably positioned on said levers and individually movable longitudinally thereof, means extending out of said frame for moving said cams long-i tudinally of said levers, and a tilt bar mounted in said frame for rocking motion and for engagement with said cams,

3.111 a push button tuner, in combination. a frame, a plurality of plungers mounted in said frame, a plurality of tiltable levers pivotally mounted in said frame for rocking motion when actuated by said plungers respectively, cams adj-ustably positioned on saidlevers and individually movable longitudinally thereof, a bail pivotally mounted on said frame, a shaft carried thereby, a second shaft connected thereto extending beyond said frame, said rst shaft being movable into and out of .engagement with said levers, and means for causing rotation of said second shaft to .move said cams longitudinally of said levers.

4. In a push button tuner, in combination, a frame, a plurality of plungers mounted in said frame, a plurality of levers mounted in said frame for rocking motion when engaged by said plungers respectively, cams adjustably mounted on said levers fand individually movable longitudinally thereof, means selectively engageable with any one vof said levers to effect longitudinal adjustment of said cams. and a tilt bar engageable and movable to a predetermined position by each of said cams.

5. In a push button tuner, in combination, a frame, .a plurality of plungers mounted in said frame, a plurality of levers mounted in said frame for rocking motion when engaged by said plungers respectively, cams screw-threadcdly mounted on said levers and individually movable longitudinally thereof by rotation of said levers, gears mounted on said levers, a worm selectively engageable with said gears for rotating said levers to adjust said `cams longitudinally of said levers, and a tilt bar engageable and movable to a predetermined position by each of said cams.

6 In a push button tuner, in combination, va frame, a plurality of plungers mounted in said frame. a plurality of levers mounted in said frame for rocking motion when engaged by said plungers respectively. cams screw-threadedly mounted. on said levers and individually adjustable longitudinally thereof by rotation of said levers, gears mounted on said levers, a transversely movable Worm movable into and out of engagement with said gears, means for moving and rotating said Worm, and a tilt bar engageable and movable to a predetermined position by each of said cams.

MARION J. PIFER.

No references cited. 

